^^^ this.
Woofer crossover bypass is pretty simple, as described. Bypassing the XO for the panel is a little more involved. See my thread on the SL3XC build for details and pics.
The next step is picking a crossover or speaker management system.
I highly recommend the DBX DriveRack Venu360, it's very flexible and will allow you to run a sub from it if you are a 2Ch-only setup. The DBX line is bullet-proof as well; they last decades powered up full-time.
modified their Sequels so they could be bi amped.
You can start simple, just bypassing the woofer XO and using a Crown XLS 1002 (~$400) with DSP to provide both the low-pass crossover needed and the extra channels of amplification.
Use a Y-splitter on the output of your pre-amp, send one feed to the current amp for the panels, and send the other to the RCA inputs of the Crown. Wire the speaker outputs of the Crown to the new binding posts for the woofer. \
The original
Sequel speaker has a ridiculously low XO point of 125Hz, and the panel can barely do that at super low levels (see my SL3XC thread for metrics on a brand new panel of that size), so I'd recommend using 200Hz using a second-order XO (24/dB Oct.) configured in the Crown.
But the ideal is to ditch the passive XO on the panel side as well, so for that, the Venue360 is my go-to tool. I'd still use the XLS1002 on the woofer, but with no XO configured, as the Venue360 is handling that. For the panel, a decent amp with Balanced (XLR) inputs is best.