Need your help!

So, I know the topic has been chewed through a thousand times etc. but I can’t find what I’m looking for. * slowly I regret having bought it audi at all * So, theme thermostat, I drive: Audi 80 B4 year 92 90Ps automatic. Servo ABT engine As it seems, the thermostat is down, so exchange, I asked once in a workshop (not Audi) who want 170 euros, am not bothered. Where the vulture sits this misstvie really the one says Wapu the andre says under the Gee On the block the other says … Has someone changed the thermostat on the car himself already, or has maybe a direct boiler where he sits? What do I have to dismantle everything and what notice, I really have no nerve on the autoi, always something broken! Who can help me now directly and tell me what I have to do and where the part sits ********** Problem description *************When I drive, the temperature sets to about 60 – 70 degrees and freezes there, quite rarely g It is possible to check the thermostat, after the moto, which hose has to stay cold and which one has to get warm if the thing works, when the fans have to tackle, what has to get warm. But since now is a lot my only help, which if I let the thing exchange expensively, and this is also sometimes higher, but in the stand it reaches the 90 degrees as it should, when it should go down again. sometimes even to the 50 degrees. ********************************************************************************************************************************************** If it does not, 170 euros are on the ar……….