We cut the top vertical tube on a diagonal and then wrapped sandpaper around the mic holder to sand the proper curve into the top of the vertical tube. Used PVC glue to glue it. This is the only glued joint.
For the base, we drilled a hole in the T-joint to fit the cross-piece. The hole was tight enough that we didn't need to glue the cross-piece but loose enough that we can remove it. Only tools needed besides the drill were a saw and also a tap to put threads in the thumbscrew hole.
We glued a piece of spongy rubbery fabric inside the lower vertical tube opposite the thumbscrew for extra friction.