Coincidence, a question about Google-Nik / Windows Gimp 2.10 came up on another forum yesterday. (although I am really a linux user)
First thing to do is go into the Partha system plugins folder and back-up the plugins you need.
Gimp 2.10.30 installs to a different folder to Partha. Both can co-exist until until you decide to uninstall the older Gimp.
Those backed-up plugins can go into your regular Gimp User profile plug-ins folder. (plugins go there, not the system folder)
C:\Users"yourname"\AppData\Roaming\GIMP\2.10\plug-ins. Since you started with Partha Gimp 2.10.22 that will already exist, some settings might screw things up. You might have to rename it and run Gimp 2.10.30 to make a new empty default, then add the plugins.
…and for Gimp 2.10.30 you find in the same place in the Filters menu:
The gmic plugin should be easy, get the Gimp installer, run it, it will find the Gimp profile and install there. Again there is a gmic profile C:\Users"yourname"\AppData\Roaming\gmic Many changes from the old gmic, best delete that and let gmic make a new one.
Wonder what happened to Partha, I hope he is ok.