Even easier, when you go to reply, see the little 'text bubble' icon on the grey background under Quick Reply? Just highlight what you want quoted, then cut and paste into that window that pops up when you click on the text bubble icon.
2019 Rockwood Geo Pro G19FD w/off road package
2015 Ford F150 XLT Super Cab 4x4 V8
<<SNIP>> I just want to copy just part of their entry.
<<SNIP>> do that?
So, yes you can edit the quoted section.
As a courtesy to the quoted poster, I suggest you mark your edits in some fashion as I did in yours. Editing a quote makes it a quote out of context, so it's just a good way to make your edits clear.
Jim & Renee
2020 Jayco Jay Feather X-213
previously 2014 Forest River/Rockwood HW 277
2006 Ram 1500 4WD Crew with Firestone Airbags
Every weekend boondocking in the National Forests or at Lake Wellington