If he is peeing all over the house then you need to restrict his access. I would also suggest you order him bellybands so that when he does lift his leg the pee will be caught by the bellyband. Cathy (107barney) sells bellybands that have a lining inside to give extra absorbency. Very well made product. I sew and have made my own in the past but these have the bumpkin barrier and now order mine from her. Here is a link to her site and she offers a YT discount.
Washable Belly Bands by T. Bumpkins & Co. and Doggie Pee Pads
Some dogs just are never fully potty trained so you need use alternatives like a bellyband. Truthfully, by allowing him to pee inside your home for years previously you allowed him to think this behavior was appropriate. I highly doubt at this time you will be able to change this behavior. When you order my suggestion would be to get at least 5 or 6 to start. They will need to be changed several times a day. Also purchase a good Urine Cleaner to clean up any areas that he has marked previously. These three simply steps will save you from purchasing an entire house of new carpeting for your friend.