You will need to copy and paste your dictionary and spell check files from the RootsMagic 4 program files to the RootsMagic 5 program files.

Locate all the files that end with (.adm) for example: American.adm and (.adu) example: Autocorrect.adu

When you paste the copied RootsMagic 4 files into RootsMagic 5's program file choose the option to replace them when prompted.