how do I do it?

I'm trying to make a conditional jump to a label:

jz newmm

but tasm says that the relative jump is out of range by 000D bytes. How do I change this to a long jump? How can I make it jump to an address, rather than a relative position in the memory?

Relative jumps are for small jumps, like you would use for if/else or loops.

So if you're using a relative jump which is out of range, perhaps take a hint that the body of your code is too complicated.

Or if you think it's still OK, then invert the test, so you branch over an actual jump.
jnz skip
jmp newmm
skip:

okay thanks