I need to install a handle release on my Hoover

I need to install a handle release on my Hoover upright vacuum. It is a windTunnel upright V2. The handle release lever on the bottom that holds the vacuum handle in place is broken. I have purchased the new lever, but can not figure out how to put it on. Or for that matter, take off the broken one. Any advise. Thank you in advance.

Renee Barden

Hoover Upright Vacuum WindTunnel V2 Model #u8141-900