Wirelessly posted (8520 (188.8.131.521))
Firstly you'll probably want to back up all your data as it will all be lost during the wipe. If you haven't then google BlackBerry desktop manager and download and install it. After installing open it and click on Backup/Restore. It's pretty self explanatory from there.
It appears your jl-cmder commands are correct. I think since you are running it on a 64bit machine it might be worth trying it on a 32bit one assuming you have access to one.