To many steps to list here. Recommend purchasing a shop repair manual for that vehicle if you want to "DIY". The shop manual will pay for itself in no time.
As long as it comes of the same type of engine out of a citroen saxo, it will fit the peugeot 106
Peugeot 106 workshop manual.
on the gear box
Petrol
No
semi synthetic or can use full sytheyic
Because I stole your diesel coil
1.75l
how do you take clips off
this engine will fit you will have to change the injecter pump as the newer one has code for it and will not match ,also the manifolds and engine mounts need changing as they slighty different otherwise they swop
Its on back side of injection pump (facing the engine front).
timing belt changes are every 70k on 106 d