That is the best way and what I should have done.I attempted to do mine without putting it apart completely, but I think they were the original seals so no matter what I did I couldn’t pull it out from the top so I ended up pulling them apart and cleaning them end to end
You bring up a point that I experience also and that is that the oil seals in these forks didn't look the same as the Yamaha oem replacements. The original seal on my forks didn't have a turtle neck on the top, just a black donut shaped rubber oil seal. Getting it out was a bit of a chore, what worked for me was a sharp boning knife poking it from the top and leveraging it out using the black plastic guard on the front of the forks as a place to lever from. I suspect that the right approach would have been to twist a small sheet metal screw into opposing sides and pull it with pliers. Less risk of damaging something doing by the book.
I'll be back into the forks to replace the metal slides in the not too distant future. Yesterday's six hour tour to Western Mass was quite nice on the new fluids. I might have a tad too much pre-load. Seals were dry.