Ok umm do I need to deactivate my ps3 accounts off of my ps3 if I change hard drives
No, you don't have to.
Here is a guide on how to replace the HDD
Remember, you must have the latest firmware available on a USB flash drive. Here is the link:
Note: you must save the file as instructed on the page, otherwise the PS3 will not be able to find the file.
A helpful video
Ok I replaced my hard drive with the old one then I tried playing borderlands 2 after playin a short time my ps3 crashed again what could be wrong?
You re-installed the old PS3, as in the one that was orginally in the PS3, as in the one you set-out to replace with a new one? Well, you knew this HDD was going to fail.
That could be the problem. Id try a scrubbing of your original HDD. You will need something more advanced than Windows format or partioning. You can find some decent, trustable freeware scrubbers that will work just fine, but its always nice to have something more professional. I like Paragon myself. Just dont partition it after words.... if you do make sure you partition it as FAT32. Also, you dont need to do a DoD type scrubbing, just a basic scrub with all zero's.
You might have something causing peices to overheat as well. If your under warrnty, Id contact SCEA.