nice boots. gore tex horrors or the proper burma's?
the insoles should pull out.
occasionally rinse the boot out with warm water. fill the boot with warm water and let it stand for 10 mins or so and then another rinse. this will dissolve all the sweat salt build up and get rid of dust/fine grit that's found its way in.
always clean them after an outing. i use a soft shoe polishing brush under the shower head. the soft bristles will remove mud and not damage the leather surface.
there have been tales of meindl being a bit stroppy if they start to fall apart and you haven't used their products so take the next advice if you wish.
rub a generous amount of wax, the stuff out of a tin/jar, well into all seams. melt the wax into the seams with a hairdryer. give the whole outer a coating of wax - apply with a damp/wet cloth so the wax doesn't stick to the cloth i.e. it all goes on the boot. allow to dry thoroughly - at least 24 hrs. i then apply a coat of shoe polish with a wet cloth in circular motion. you will now have nice clean shiny boots.
the polish just provides and extra layer over the wax. thereafter i use nikwax water based liquid stuff when they need it.
but when do they need it?
after washing (or even when out) you will see "wet" patches. if these "wet" patches dry in about 10-20mins the leather isn't wet, it's just the surface wetting out. areas that haven't dried need some liquid wax - these areas will usually be the flex points as that's where wear on the original wax application rubs together the most.
lately, i have stopped using the nikwax liquid since i got hold of some of meindl's own sylproof - in a tube - which is excellent stuff indeed. however, i think they may have stopped producing it.
i always treat boots this way when brand new and more wax (the tin stuff) on the flex points after they've broken in i.e. all the flex points are well defined.
the tinned wax shoul dbe be used only occasionally as it will soften the leather over time and you could end up killing your boots with kindness.
so far i've been fortunate in never having a faulty pair of boots.