@SpookDog Hey bud, didn't think I'd seen you on here for a while 
You can remove the relay arm without taking the swingarm out, and at both ends of the dogbones there are just plain bushes (the needle roller bearings go where the relay arm attaches to the frame). However at the upper end of the dogbone the bushes are in the swingarm so if you have the time, I personally would take it out which will make the job a lot easier, and it's also a great time to replace the swingarm bearings and set the swingarm side clearance if you haven't done this already.



This guarantees perfect chain/sprocket alignment and without the rear wheel/linkage fitted, you can get the arm to fall under its own weight with <1mm side-to-side play even with the swingarm pivot bolt fully tightened. A lot of the "specialist DTR restorers" on Facebook etc. miss this step but it makes a huge difference to the bike's handling and chain/sprocket life.
From memory I think I always just drifted the linkage bushes out with a hammer and punch, and pressed the new ones in in the vice using a socket. Same goes for the needle roller bearings except I pressed these out as well, and be sure to take out the grease nipple first otherwise the outer cage of the roller bearing will vandalise the protruding end of its thread as it goes past.
The linkage bolts with grease nipples shouldn't be worn at all because assuming they're done up tight with the linkage assembled correctly, they, the bearing sleeves and the dogbones form a rigid sub-assembly and so should never move relative to one another.
If you've bought the eBay linkage repair kit, unfortunately the long inner sleeves (i.e the tubes which fit between the linkage bolts and bushes) lack the 2mm holes necessary to allow greasing of the pivots via the grease nipples. It's well worth getting these drilled as it makes a massive difference to how long the bushes last if you keep re-greasing them. I say get them drilled because I think they're case-hardened; I once tried doing it myself on a pillar drill and even using a cobalt drill bit set that cost me 50 quid in Screwfix, I couldn't make any impression on them so this needs doing by some engineering firm somewhere.
If you have double-lipped seals from Simply Bearings etc., another hack you can do when assembling the linkage/relay arm is to flip the seals so the garter spring faces outwards away from the bearing; the lip without the spring is just a dust wiper so you can then cut small sections out of this with Swiss Army Knife scissors (best/sharpest scissors I've ever used) or one of those leather punches so when you re-lube the linkage bearings with a grease gun, the hydraulic pressure is less likely to force the seals out. The grease is free to pass through the gaps in the dust seal lip (now on the inside) and lift up the lip with the garter spring in its bid for freedom! The sprung lip then retracts, retaining enough grease inside the bearing and keeping dirt out.



If like me you're ham-fisted with the grease gun, it will still try and force out the seals so you can also hacksaw a section out of an M20 x 3mm washer and insert it in the gap between the tiebars and the arm during greasing to prevent this (with the linkage bolted together and the seals where they should be, you can actually move the tiebar/sleeve assembly 2-3mm side to side; useful after you've greased up everything as you can move it fully each way to make it splodge the excess grease away from the bearings/seals, then clean it all off thoroughly to prevent any getting on the rear tyre).

Lastly I'd also replace the lower rear shock bushing as this usually wears before any of the actual linkage bearings. It's held in the shock by two of those PITA C-clips and IIRC I destroyed a Lidl precision screwdriver set getting them out (mind your eyes as the speed one of mine flew out, I think explains why the Northern Lights were visible over Dorset that time). This one fits the DTR:
https://www.mandp.co.uk/products/29-5027-lower-rear-shock-bearing-kit-605946
All sounds like a lot of work I know but being able to externally grease up the rear suspension is one of the greatest features of the DTR, done like this you can just ride the bike week in week out, 10 minutes with the grease gun every week or two and you'll probably pass next year's MOT without even having to look at this again.