Temp gauge not working on felicia, have followed all threads and reck it's gonna be temp. housing and/or sensor. Coolant also looks brown mucky and in need of a flush.

Any one done this, is it easy / difficult, need bleeding etc etc. Do I need Skoda replacement coolant or just regular anitfreeze + water ?

any old antifreeze will do... you can either use the drain plug in the bottom radiator hose, or if yours doesn't have one just take the hose off the bottom of the radiator

Drain the coolent from the large hose at the bottom of the radiator!! The plugs have a habit of perishing and can snap easly! Have done it in the past and its no fun trying to fix it!!