Patch Changes mid score. | MuseScore

Apologies if this has been answered elsewhere but I cant find it.

In MS3 we could change a sound of an instrument midscore by adding stave text and selecting the patch. (For a guitar it was things like Harmonics, distortion etc)

Now Im on MS4 (Linux) and these things dont seem available.
Been reading similar question recently re pipe organs with stops etc.

For example, I have a E-guitar part that for 24 bars is a clean sound. Then there is a 8 bar section with a solo sound. Then back to normal.

If I add a change instrument, and select E-Guitar, nothing extra shows in the mixer so I cant change the sound.
Ive tried looking at maybe using a different voice, alas it seems a stave if fixed to the same sound for all voices.

Hows is this now done ?
Thanks in advance.

Paul