Re: 156 Thermostat replacement - pig of a job
This is a difficult one, and the chances are it will snap, but the best way of approaching it to reduce the odds is to buy some good quality penetrating fluid (not WD40..I use stuff called Penol which is good, but any similar product will do).
Spray it every other day for a week or so, and also apply heat to the bolt head. You may need a gas torch with a pencil flame (small thin flame) to target it correctly with enough heat without setting car on fire or doing damage.(I'm assuming its not a plastic housing on a TS..I only know the 2.4JTD)
Don't be in a hurry to try and turn the bolt, but when you do don't force it, ease it back and forth gently. Also tap the bolt head with a small hammer (I don't mean whack it)
I have won some and lost some using this technique, but I'm sure I've succeeded on some I would have broken if I had been less patient.
Incidentally this method was taught to be by George..mechanic in the 8th Army in the desert in WW2. When I was 17 he was the mechanic at our local Renault garage where I had a summer job. Ace guy, much missed.