Never done anything like this before and my brain was about to explode after all the reading and searching, on how to do this....seemed like everywhere I went, it would say or I was told that I would have to go back to stock and start all over with it.........so I thought, well shoot since its all ready rooted and flashed to Cricket, I will take a chance, and I'll just skip going back to stock and just start with backing up my apps with Astro from the market, and then I downloaded Rom Manager from the market. Now, in the Rom Manager I went to Backup Current Rom and backed it up with no trouble, and then I did the Flash ClockworkMod Recovery from inside Rom Manager,,,,but when I did it would just freeze up and then force close, tried it several times, then I happend to notice, as I was scrolling down the page in rom manager, that at the bottom it said All Clockworkmod Recoveries,,,so I tapped to open it and it showed 4 versions, so I pick the 126.96.36.199 tapped it, and it flashed with no trouble. then I hooked my phone to the computer and copied/paste everything on my SD card to a folder on my desktop, just in case anything happened, I had all my apps saved and backuped.
Then I downloaded the CyanogemMod 6.1.6-droid zip file and then downloaded the google app zip file, that went with that Rom, copied both to my computer desktop, and then placed both of them on the root of my SD card........after that I went back to the Rom Manager and went to Install Rom from SD card, I found the Rom and tapped on it and it asked if I wanted to backup existing rom and if I wanted to wipe data and Cache, I tapped on both and it downloaded the Rom....it didnt take long either.....and when it rebooted and turned on, the rom was there ....so then I went back to the rom manager and to Install Rom from SD card again, and found the google app (gapps) and tapped on it and it asked me the same as before, so I tapped on both and it did its thing........it rebooted and when it loaded this time I could sign in to my google account because the 3g data was working.....Now at the time I didnt have mms picture ....I just did what it said at the first post and set my APN setting.
You can do that easy by going to market and downloading Anycut...open up anycut, and it will have a button that says, new shortcut, tap on it, and then tap Activity....scroll down to where it says APNs and tap it, then tap ok...go to your home screen and there will be a icon there that says APNs, tap it, now at the top it will say Verizon, Tap it>and it will open your settings....you Change All settings to what it says on the first post....or on page 13 post #122, then hit your menu button and tap save...Now once you do that it will close and it will say Cricket at the top...NOW MAKE SURE THAT YOU TAP THE DOT TO THE RIGHT OF Cricket so it turns green....if you dont, it wont save your settings, and the first time you cut off or reboot your phone it will revert back to Verizon settings.
Sorry for the long story here, I was just happy and wanted to share, just in case someone else was already flashed to Cricket and had 2.1 and wanted to go with 2.2.1 and thought it might be too much trouble.....it sounds...well, it writes out to be alot lol....but it's really not all that hard once you figure it out.
here's the names of the app from market I used and the links to the Rom and google apps. I used the 6.1.2 Rom, but I'm sure any of them would work, or I hope...and remember you have to pik the google apps that go with the Rom.
Good luck and I hope this helps someone, if you can understand what I wrote