You need to contact a lawyer in the jurisdiction where the warrant is issued. The underlying issue, the alimony, will need to be taken care of first. A good lawyer may be able to negotiate or abate the amount even at this late date (it should've been taken care of before it got to the warrant stage so negotiation may not be an option, but should at least be attempted). Then once the underlying issue is taken care of, then the lawyer should work to get the warrant revoked and removed from the system.