There are aftermarket solutions, no need to adapt your Tesla. They are however V2L, not V2H, which may not be exactly what you need.
See e.g
There are also home DC charging solutions that permit bidirectional charging (V2H) but they cost around 10k last time I checked.
I considered these solutions myself and concluded that it's not worth the hassle as they are unsanctioned by Tesla and support could be removed anytime. I'm planning on installing a home battery instead to take advantage of my excess solar generation.