How do you install a 165x76SEMAtensioning spring on a Murray riding mower

Not sure which spring you mean, as there are a few, but this series of videos pretty much covers all the repairs you may encounter*.

165x76sematensioning spring on a murray riding mower - Bing video (http://www.bing.com/videos/search?q=165x76sematensioning+spring+on+a+murray+r iding+mower&&view=detail&mid=FAFC0FD31D20276FDB5BFAFC0FD31D20276FDB5B&rvsmid=FAFC0FD31D20276FDB5BFAFC0FD31D20276FDB5B&FORM=VDMCNL&fsscr=0)

Let me know if they help.

*Don't let the different makes/models shown throw you as the process and procedure are fundamentally the same.