How to switch properly from XnView to XnViewMP

[aapapapa]

One can't find any single word about how the proper procedure of upgrading the XnView legacy
to MP has to look like.
- legacy to be completely uninstalled prior the installation of MP?
- MP just to be installed over legacy?
- MP to be installed additionally and beside of legacy?

Which one ensures the best results regarding stability and lack of troubles
while using MP?

[xnview]

you can have the 2 versions...