I think on a 93 306 you can renew the gaiter without removing the
shaft. It involves gettng the shaft out of the hub, cutting the old
boot away, then hitting the end off with a couple of smart blows from
a hammer. In a Peugeot boot kit you will get a boot, two clips, grease
and a circlip. ALWAYS renew the circlip on the end. Then push the end
piece back on the shaft up to the circlip, and with a small
screwdriver compress the circlip into the groove while pushing on the
end. Now hold the tension on the end and hit the end smartly to locate
it on the shaft. You should only need to hit it a couple of times.

The problems. The left hand shaft is harder to do than the right hand
one, because you have to prevent it from coming out of the gearbox
when you hit the end off. The right hand side is fixed to the centre
bearing.
If you have the type of inner gaiter which is rubber and metal then
you cannot hit the outer off. The best method is to remove the
driveshaft and take the inner gaiter off and then the outer past the
inner (if that makes sense). I have never been able to use the stretch
type with cone. And don't even think about the split type which you
glue together. They're a complete waste of money IMO.
If you do remove the driveshafts, renew the seals in the gearbox.
Oh and good luck!