DOES ANYONE KNOW THE LOCATION OF THE CRUISE AMP IN A 1986 190D, 2.5? IS IT HARD TO CHANGE IF YOU'RE NOT AN ACE MECHANIC?

Yeah. i had a problem with that basterd too
its located under the kick panel (the floor) on the passenger side
it looks like a big grey relay..
when you remove it make sure you do not touch the big black relay (ALARM if you have it) or disconect any blue wires (airbag if you have it)

Concerning replacement... its not hard at all just remove the wires going to it and put in the new one