You mine by keeping your wallet open with coins in it. There is no conventional mining.
On another note if anyone has a mac we need to test the MNTA OSX wallet. 100 MNTA bounty. https://mega.co.nz/#!XBBVkL4A!Pq-1pN3iA6oFcGOcehnMA2y7aU1K6afbVf-i0Ts_ygw