Wether a DIY selfer can do the job or not depends entirely on his mechanical experience and skill. The blower motor on your 124 chassis car is not a piece of cake like they used to be on 123cars. It's an easy job for an experienced pro but before you decide to tackle this or any other job yourself. You should ask yourself,1:do I really know what I'm doing here? 2;How much am I saving if I goof and screw something up?
A good example, I just finished building a 427cobra replica to cruise around and play in. It was really simple for me,but I've been a mercedes tech for 18 years and have about 8 years roadrace car fabrication experience. Now,if I try to cook dinner tonight for my wife,I gaurantee you that she'll have to either kick me out of her kitchen or call 911 to put the fire out before I'm through. Happy motoring,Alain