Not sure that this will be an easy task!
IIRC, the LM 62 windscreen is taller(10mm?) and is more raked than standard by some rather crude machining on the screen brackets. This might have been so that the top fitted a "long-door" tub.I believe that one size of top was used for both 4/4 and Plus 8 variants. I have the 9 stud windscreen.
On my car, the front clips on either side attach to purpose-slotted A-posts. The single rear central clip attaches to bracket mounted just below body line. On either side of the seats vertical brackets fitted to the body screw into the hardtop. If all fittings are not very tightly secured the top can move about or even detach.
Not at all sure that I have described this coherently so would try to post photos, but will need help with this!
Andrew Green
Glorious Devon
Le Mans 62 Plus 8