I will retire in 2 months I want to roll my 401k over into the best instrument for monthly income to supplement my pension & social security how should I proceed

You apparently want monthly income on a regular (monthly) basis - if I were you, I would open a roll-over IRA account with Fidelity and move my money into a tax-free mutual fund (I live in California and so would probably choose the Fidelity
California Municipal Money Market Fund and invest it there perhaps.. just a thought --