Well, I'm not sure how to do it exactly. What happened was I got stationed in LA while my FL driver's license was still valid. So I just took my orders in to get a LA ID card. For proof of residency that's all you need for hunting/fishing licenses... so in that respect, I have residency in both states.
Suggest you go to LDWF website and look at Residency requirements. Also if you obtain a resident hunting license in any other state you cannot possess a resident La. license.