You don't even have to import to excel. Just do the following steps:
1) Load your existing saved codeplug into CPS (latest version you have)
2) Go to Tool > Export, and save the file with a unique name
3) Figure out what MODE or band the radio is presently set to. Use menu Model > Model information. Under Frequencys you'll see a MODE number. Write it down.
4) Copy down all your Optional Setting - take screen shots or write it down by hand. This information isn't backed up by an export from step 2, unfortunately.
5) Start a new codeplug. Use menu Set > Set Initialization
6) Confirm the new codeplug is using the same MODE band from step 3. Use menu Model > Model information. Under Frequencys you'll see a MODE number. Make sure it is the same number you wrote down in step 3.
7) Now use menu Tool > Import and load the unique named file you saved in step 2.
8) Input all your Optional Setting from step 4.
9) Save file, preferably noting the version of CPS software you're using in the file name.
10) Reset the radio by holding PTT and the button directly underneath it while turning on. Confirm the reset. Once done, write the codeplug to the radio. That's it.
This process is called 'rebuilding' your codeplug, and ensures the entire codeplug data is freshly created & consistent with the version of CPS & Firmware in use. It needs to be done every time you update firmware version in the radio. Otherwise, it should be good to edit, add, etc any channels or other changes you want to make without this rebuild process.