How do I install a replacement leg clamp on my manfrotto tripod?

SOURCE: Broken leg clip on Manfrotto Modo 785B

Yes you can. But I saw that your Manfrotto is possible to buy for 50 Euro.
Anyway the part you need is the full leg called CODE:
R785,203B
you can see the datasheet on the spare part site of Manfrotto:
http://www.manfrotto.com/webdav/site/manfrotto/shared/manfrotto_nord/pdf/7/785B_20070503.pdf
Regards
PDG

SOURCE: i need a lower leg clamp for my 190xb manfrotto

Hi there,
You can order the lower leg clamp as a part from http://bogentripodparts.com/parts/190XDB.htm
Follow the link and check for your part number.
Hope this helps,
Andrew

SOURCE: Broken leg clamp, Where can I buy a replacement part?

Try www.BogenTripodParts.com for that part. There is listed the widest selection of Bogen parts and support more models than any other web site I’ve seen. There are losts of pictures to help find just the right part

SOURCE: Lost quick release clamp on tripod (manfrotto)

Try www.TripodQuickRelease.com for that part. There is listed the widest selection of quick releases and support more brands than any other web site I've seen.

SOURCE: Broken leg clip on Manfrotto Modo 785B

You can oredeer parts from
www.bogentripodparts.com