You can top off the DCT; there's a solid DIY in the DIY section or you can use TIS. If it is the sleeve that's leaking then I hope that quote involve dropping the trans to do it. I know someone previously mentioned that they were able to replace theirs by tilting the trans back, but its going to be very tight:
https://www.m3post.com/forums/showthread.php?t=1697657