No modifications!
Under no circumstances are roof trusses to be modified on-site. If trusses are forced to work in ways they were not designed for, problems will develop.
Cutting the bottom chord will cause the other parts to work
more in bending than axial loading. The truss will sag and break.
Cutting a web will cause the truss to be no longer a pattern of rigid triangles.
The truss will become unstable and distort out of shape.
The bottom chord is designed to work mainly in tension. If the middle is wrongly
supported by a wall, the chord will be put into bending. The truss may break.