Installing SunHelm is simple. Just download the mod with your desired mod manager, and install as usual. The main download includes a fomod installer, allowing you to choose appropriate patches.
I recommend Mod Organizer 2. However, Vortex is also a good choice. Manual installation is not supported.
SunHelm requires. (Not optional)
SKSE
SkyUI
Powerofthree's Papyrus Extender
Not Required but strongly suggested
Survival Control Panel
JContainers (Required for MCM profiles to work)
Completely Optional:
If you want to use the Campfire Skill tree, then you can also install Chesko's Campfire.
Through the MCM menu after Skyrim's intro is completed.
Sleeping in a bed will also prompt you to start SunHelm.
After starting the mod you will be shown a quest completed message, and your needs will activate. At this point it is safe to enter the MCM and begin altering settings.