Advice on upgrade

Aside from the usual non answers there appears to be some consensus that you may want to start a serious assault on the summit of a well integrated synergistic system by looking at changing your speakers. It is an old axiom that the speaker accounts for the vast majority of the sound quality and flavor of any system. Therefore start by building around your speakers.
Personally I found that the amp I use has a very, very important role as well. I finally switched to tube power amps with some unusually good trannies and my system came alive. People kept asking how I had modded my speaker after that amp change.

size of light bulb or ping-pong ball, but you shouldn't remove it completely.

You gotta be a vet surgeon specialising in ORL and elephants...ah, a wolf.
Back to the OP, you may want to upgrade your interconnects and/or speaker cables.

Using ear drops and the warm water bulb to remove earwax is utterly safe and works really well. It just does...I've removed lost car keys, maps of Cuba...

But what happens when the ear wax is the size of a ping pong ball?

removing ear wax may damage your ears. it usually falls off on its own

Modest tweak: Ear wax removal...from your ears (if there's ear wax anyplace else...well...that's just creepy).

depends what you try to get from upgrade...
changing speakers may give you the most roi.

If you haven't 'tweaked' the system with AC conditioning, isolation, room treatment, etc...I would do those types of things before changing out components. I've had a couple of systems similar to yours which benefitted greatly from modest priced 'tweaks'.

Not sure how you wired your speakers but your source = Rotel CD and whether you like the way your speakers sound look like areas that might be changed.