Firstr of all jack up the rear of the car high enough so you can crawl under it enough to access gearbox area.

For reference the area your trying to find is here:

Theres 2 to do and looking from underneath its these 2 arrowed:

Both ethe bearings are held on with a clip which is easily removed with a pair of thin nosed pliers - TBH I reckon you could do these with your hands but why struggle :-)

Can be a bit stiff but after a bit of wriggling the bottom one came off. Once off just use your fingers to press the rubber bearing out from the linkage cable.

Its made up of a sandwich arrangement of 2 washers, rubber bearing with metal insert and topped off with the clip like so:

And well just be replacing the rubber insert with the stainless bearing )(kindly supplied by Jamie at Jap spec:

I applied a smidgeon of grease to som eof the surfaces and pressed the bearing into the cable end. I found it a bit awkward to then get the cable back over the link but after a bit of messing I realised the secret is to look at the link side on and make sure it is going on square to the post otherwise it just wont go!

Bottom one done :-)

The top one is a bit more tricky to do as the bottom link is in way - you may evcen want to do the top one whilst the bottom one is disconnected to make it a little easier - up to yourself but I wasnt bothered.
Remove clip again with pliers:

Now I had problems here - I had to "chisel" link off with screwdriver and it tore the rubber bush leaving a piece still on post. Wasnt getting anywhere so decided to remove link - first remove rubber cover:

Then remove securing nut with 12mm socket - its not on vert tight at all:

Even off the car the rubber collar was stuck fast - may explain my wonky gear changes! Note partially damaged other piece of bush.

I had to heat the link up with a blow torch then using mole grips to initailly get it moving I then gave it copious amounts of WD40 and wrangled the thing off:

I hadnt cleaned the lower post up but I thought I had better do this one as it had corroded slightly - hence the bush collar sticking to it. Just used some wet and dry for thius.

Just a question of applying a smear of grease on moving parts then rebolting up link - dont forget to check it still moves freely then put cover back on. Reasseble link as per bottom one then put clip back. Again, if you put bearing in end of cable first make sure it is square on to post otherwise it wont go.

Let car down from jacks and job done :-)
I wouldnt say my bearings were particularly bad except for that stuck one but I have noticed an improvement in feel - feels much tighter so well worth it IMO and a cheap mod/fix to do :-)