i haven't seen this posted here at adroidforums so figured i'd give a heads up.
you need CDMA workshop.
1. connect phone to computer
2. enter diag mode by pressing ##diag# on your phone's dialer
3. hit connect
4. click on "Other" tab
5. under PRL, click write and navigate to the PRL file
6. reboot phone
edit: apparently this doesn't work with CM6 ROM. if you are rooted and using something other than a stock ROM, please make sure it's based off of the 3.26.651.6 build.
you need CDMA workshop.
1. connect phone to computer
2. enter diag mode by pressing ##diag# on your phone's dialer
3. hit connect
4. click on "Other" tab
5. under PRL, click write and navigate to the PRL file
6. reboot phone
edit: apparently this doesn't work with CM6 ROM. if you are rooted and using something other than a stock ROM, please make sure it's based off of the 3.26.651.6 build.