This should help
http://www.talkmorgan.com/ubbthreads.php/ubb/showflat/Number/229212/Searchpage/3/Main/17438/Words/cambelt/Search/true/Re:_Cam_Belt#Post229212
I have replaced mine it took about 40 mins. The instructions above will work but you do not need to remove the crankshaft bolt and washer, only the idler pulleys. To keep the tension off the tensioner I used a piece of rope tied to the spanner and then to the indicator support, this keeps the tension off and you can then fit the belt.
