I bought upholstery covers for my front seats (79 450SL) and bought the book from **************.Com on how to restore. All has gone well until I get to the step where you take the side supports off the upper portion of the seat. The book is strangly silent on steps. There appears to be 4 bolts and for the life of me I can't get them out. I've had some stuck stuff on other parts, but I've always managed to get them loose. Is there some sort of trick? Also, the bar that runs through the middle that controls the recline - will I have to do something to get that out, or what?

Any help is much appreciated!