Do you HAVE to take apart the fork to change seal?

Mine in a nut shell said to put some fork oil in and pump the fork a few times to fill the valves. Then with the tube extended (bike jacked up so the front tire was off the ground and measure the fork oil to 17 & 15/16's inches from the top. -or- 455mm. The forks are not locked up. But I thought the ride would be a bit softer than what it is but the ride is not harsh by any means. But still a little stiffer than what I had with the 43 year old fork springs. I'm not really complaining though. Tim

I might be wrong about the measurement. I'll have to look again. Mine are about do too. I have progressives as well. I had the original stock springs before. Not a big change but I feel better having modern ones in there now.
Steve