What would be the best use of 140k

[Chris Kurisu]

Earned 8% on 213k invested last year but moving to safer harbors, very likely to be closer to 5% next year. Carrying 235k @5% on a refi from '14 (don't ask) and have a strong desire to reduce the mtg pmt. Value $510 and rising 5%/yr on average. No debt besides mtg and a car loan. 720 credit. 

Considering pulling 140k from the market and using it to reduce the mtg pmt but paying down only moves maturity closer. Cash-in refi? Recast existing mtg? Any suggestions?