You might be able to find additional RGB TV modding information for that particular CRT at either CRT Gaming Subreddit
or shmups.system11 forums
. As krssn said, you should always discharge the CRT before doing any servicing/modding and only if you really know what you are doing. Recall that CRTs can have a capacitance in the multiple Farad
range (high enough to hold a charge for years and kill you).
If no RGB mods are available, I'd keep an eye out for either a cheap moddable CRT, a Sony BVM/PVM, or an IDC34 RGB Multi Input monitor. Sony BVM/PVM CRTs have BNC connectors for RGBs/RGBHV inputs, while IDC34 monitors (such as the Sony ProFeel KX-2501a or certain NEC monitors) have a proprietary IDC34 floppy port. This port has all of the signals available for a RGB setup, and a DIY circuit can be created to interface SCART
or BNC (RGBHV+RCA Audio)
to the floppy port.
I have a Sony KX-2501a that I found for dirt cheap, and RGB works spectacularly with such an interface circuit.