You should be able to just install a rebug DEX Cfw ( e.g. 4.46 ) via USB???
If not.....then you will have to...
Download and install the 3.55 DEX downgrader
Once installed you will be back on 3.55 DEX.
Install 3.55 ofw from the recovery menu via the system update option ( MAKE SURE YOU HAVE NO DISKS IN THE DRIVE!!!! )
Once 3.55 ofw has installed you can either...
Install rebug 3.55 DEX then update to a required rebug DEX Cfw
OR....simply update to a rebug CEX Cfw,install rebug toolbox then convert back to DEX via the rebug tool box using your CEXDEX norbins.
Hope this helps
Good luck