Hi!
Ok well even if u are not interested in 3d working Blender is free and can be useful, for simply converting oblivion nif or to convert armor for different body model.
There is not a software in the world i recomend more highly!
But anyway, yea what u want to do for this experiment is only involving nifskope.
I mean it is an experiment, cause it would be clear cut to create brand new colision mesh, but if u just replace hkpackednitristripsdata instead u can learn if this particular colision mesh shape has any effect on its function.
for using nifskope to replace just the geometry data what u do is find another nif with a hkpackednitristripsdata, remove the geometry data (hkpackednitristripsdata) from original mesh,
copy just the geometry data from the mesh u found and selecting the parent bhkpackednitristripsshape and find data field at bottom of blolck details window and paste new data there.
It might work or not, dunno.
If u want to make new colision mesh in nifskope without blender, u can use this tutorial tho.
It show u how to convert any nitristrips or nitrishape into colision mesh with only nifskoep.
http://cs.elderscrol...p_by_Step_Guide