the one relay i have managed to remove took near as dammit half a day to get out, i ended up cutting the lugs that are welded to the chassis off so i could get a massive set of stilsons on the top of it to twist it in the hole to help break the rust up
once i eventually got it out about 1/2lb of rust fell on the floor and the tube looked like it had been containing an ostrich egg
it's a good relay that was in a knackered chassis and i really wanted to experiment in case i ever need to get one out to perform welding repairs