Hi Massichat. I also have no "knowledge in theory," and avoided any edit of styles for a long time. But after trying and exploring the style editor a little bit, I found it easy and comprehensive...

From what I understand u want to do, u can do it in two ways;

1.Make any bassriff in the melody/soloist track. Export it as a midi file. Then go to "File/Stylemaker/Stylewizard, and import the riff u want. Just assign the track u just made to the basstrack.

2. Open any midi style that have a basstrack u like, and open "File/Stylemaker/Edit current style"
There u click on the bass track, then on the note icon to the right of the red record button. This will open the note view windows. Here u just click on the "Edit note" box at the top left, to the right of the print box. There is 3 boxes there. Use the one in the middle. Now u can edit or insert any notes directly with the mouse. If u just want to edit the existing notes, click on the boxes in the main windows that has a number in it.(Usually number 5) and the notes will be visible. If u want to add a riff, click on an empty box. That will take u to a blank part of the note windows and u can insert any notes there to make the riff u want... Then insert a number from 1-9 in the box. Low number, will play it seldom. High number will play it often...

Hope this helps...;)

Forever Grateful, BUT, sometimes pissed of. wink
Trygve "Leo" Larsen
BiaB 2020, Windows 8.1, Intel Core i5 CPU, 270GHz, 32 Gb RAM
My OLD tracks on Soundcloud; https://soundcloud.com/trygve-larsen My NEW is unpublished
The Universe = Uni-verse ie one song.