I would like to know how to take my old buckle off the strap and put this one one on?
take it to a shoe repair shop it will need to be stiched on :) make sure it faces the right way or the velcro wont work
Take it to a shoe repair shop and have them sew it on use nylon thread cotton will rot.
I followed directions from an internet article "How to Put a Scuba BCD Belt Through the Buckle". google this article.
also google the video "SCUBA BCD Tank Strap & Buckle Safe Assembly" that help
There are two ways.
First cut the old strap off. I just slide a knife between the webbing and cut the threads. Then put the new one on.
Best method is to loop the new web through the metal ring and sew it on with several lines of heavy duty thread. This requires a sewing machine
Alternate method is to use a wide slot weight keeper and thread the webbing up then down through the keeper, through the metal loop and then back through the weight keeper again.