No, just created a new 100M personality within RPM and write that into the radio. If you want to read the existing codeplug then yes I would presume you are going to have to use RPM2 since 14C05 is the last version of RPM1
And to keep it simple just for starters, make the first personality you create very simple; one conventional frequency set, one system. Once you've got that into the radio successfully and ensured that no problems cropped up, you can create a new personality with whatever you want in it.
And when you do start creating a new personality file with all your stuff in it, it's best to do it one frequency set or group set and one system at a time; load that into the radio and make sure no errors appear. Then save as a new name, add the next frequency or group set and system, and load that to the radio, making sure that no errors appear. Repeat as necessary.
Takes a bit longer that way, but it makes it a
lot easier to track down problems as you go.