This is how to use F3x (Btools) advanced
Part 1: The basics
The move tool: Z
Resize tool X
Rotate tool C
Weld tool F
Texture tool G
Mesh tool H
New part tool J
Part 2: More advanced
How to weld items together
Select one part then ctrl-click the next one then press weld to last.
How to select items in a group
Press Shift+T to select items in a group.
This also works for the coloring and texture tool.