Wish I knew.
Lets think on it

A fractional distillation sounds difficult.
Will need tight temperature control in a closed system.
Don't want to just "burn off" THC, it has medical uses.

Might be able to do a column separation, but it will be messy and imprecise.
Analytical chromatography might be doable but requires some skills.
A preparative gas chromatography is ideal, but way beyond my means.
I'm wondering if it would work to separate the components in their acidic form and then decarb with heat.

Also wondering if THC and CBD can be persuaded to become salts.
That might simplify the fractionating.

If we all go ponder this, and do some reading.
We can probably figure this out.

Meet you all back here in a day or three.
Lets see what we can see.

Obligatory Disclaimer:

I am NOT a chemist.
Don't even play one on TV.
I'm just some guy on the net who reads way too much.

Aloha,
Weezard