The safest way is to pay a professional, but even with that, there is always a chance of paint damage. I have seen the work of a company in Ft Myers called Ugly Shield Removal. I am going to have them remove mine. It is around $1000 depending on the install area. I helped a friend remove his and it was a messy and time consuming job, never again.
The most common way to remove is a scraper and heat using a heat gun or steamer. Then when the plastic is off, they use a chemical and scraper to remove the glue. Not hard, just messy and alot of scraping and cleaning with solvent. Ugly Shield has multiple videos on how too, just google.
Steve and Livia Of Tampa
2007 Country Coach Magna 42’, HWH Active Air, 600 ISX
2013 Honda CR-V