That medium looks bad enough that I'd suggest go ahead and repot. Don't worry about getting all of the old medium off - leave anything that is stuck to roots. Just get rid of what comes off easily. You can help to separate roots from the walls of the container by gently squeezing it - if you can't get it loose that way, don't hesitate to cut the pot. (There are some really good-looking roots, you want to preserve them) Then into a larger pot, add some large bark, tap to settle it in around the roots. Press gently with your thumbs away from those long roots. It is important that the plant be held firmly in place so that it does not wobble (which can damage newly-emerging roots) but beyond that, you don't have to pack the medium.
Thanks Roberta, got it moved to the bigger pot. Felt like I left a lot of the old medium, but the roots were everywhere and had lots of medium stuck to them. Seemed like a lot of dead roots as well, but I left those alone. I'm pretty sure I've gotten a little crazy with root trimming in other repots so held off a bit on this one. We'll see what happens!