You put honey on a sweet smelling tree and come back to it about 6 hours later and hope its a munchlax. But there is a 1% chance it will be a munchlax. You could also use an action replay or ask someone that has one to breed and give you one.
Underground goods (L+R)
94000130 FCFF0000
B21C4D28 00000000
B00000004 00000000
E0004544 00000028
29565726 35343314
852B3736 2C47550F
7B0E3D76 0000002E
00000000 00000000
00000000 00000000
D2000000 00000000
I ALSO HAVE A CODE FOR 50 FLAGS:
(L+R)
94000130 FCFF0000
B2101D40 00000000
00003CFC 00000032
D2000000 00000000
HOPE I HELPED