How to dump fuel from jet?

[Fullmetal Analyst]

i have some useless fuel left in my jet, is there any way to dump it?

[Tsani]

Find a drone

[VlonaldKerman]

Poke a hole in the side. Works IRL.

[Gargamel]

Moved to gameplay questions. 

[Streetwind]

Not to my knowledge, no.

Don't expect this anytime soon either. KSP1 took like 10 years of development to get around to it, and even then you needed to add a special part for it.

You can, however, attempt to transfer it to a central tank where it won't affect your CoM as much, if there is an issue with that.