How Should I Go About Refinancing My Home?

refinancing

I have a mortgage loan at 6% with a balance less than 80,000/8 years. Should I refinance the balance that I owe to invest my money somewhere else? Would it be worth refinancing with only 8 years left? I was thought about purchasing a new home and renting the current one that I have. The market where my home is very excellent for renting. Thank you.