I went back and searched fork oil change, and found some guys are saying to take the fork tubes off the bike and wipe out the inside, and run some brake cleaner in there as well. Is it that big a deal if the forks just drain while on the bike, and how much will the residual old oil throw off the measurment, unless I catch the old stuff and use that amount to add back in as posted earlier

 

The manual gives measurements for dry fork and wet fork. Dry fork being new or all cleaned out of oil. Wet fork is just drain and refill. The measurements in most of the threads are for wet fork. Check your manual for your bike. I use 11oz for wet fork. 2010 street glide is 10.7 I figure the oil that sticks to my measuring glass that does not get in fork I am sure I put in just under 11oz. Same way I did it on my 98 street glide for 12 years and never had a problem.