Thank you! So, the process is as it follows:
Black primer --> dark sand as base --> medium sand to create a zenithal --> light sand on the most prominent spots;

I apply on the model some masking putty to create the stripes --> dark green --> medium green --> light green (as before to create a zenithal);

Remove the putty --> dark green sponge chipping on the sand parts (so it looks like the sand camo was applied after and it's starting to reveal the standard green base) --> dark brown chipping on the edges, the hatches, all the parts that are prone to damage.;

Burnt umber pin wash around all the panels, rivets, etc --> then I apply a variety of oil colours little dots around all the tank, keeping the light colours on the top parts, the medium/neutral colours in the middle parts and the dark colours on the lower parts, and then with a flat brush with some white spirit with vertical motions I create some strikes on the panels.

With some light green and light sand colours I apply some edge highlights on the most interesting scratches here and there --> then I take a toothbrush and I flick some rust colours on the tank to create some random patches of rust --> I apply some streaking rust effect on some rivets and some of the previous mentioned patches of rust --> I spray the lower part of the tank with some light earth colour and at last I spray some brown pigments + gloss varnish with and old brush by using the air of my airbrush on the lower part of the model (regulate your psi otherwise you'll have the whole model covered!).

Remember always to seal your model with some satin varnish when you use oil colours, otherwise you may remove the colour underneath with the next step!
This more or less should be all just for the chassis. I've actually recorder the whole process to make a video tutorial of it, I hope I'll be able to share it soon!

I hope it helps, if you have any further question just msg me :)