How to become ambidextrous
How I did it: I'd spend about an hour a day (Yes I had too much time on my hands and I hated school work) and I'd practice. pick up a ball and throw with my right (slowly) and then try do it with my left the same.
Kick a ball with my right, in all the different funny angles soccer players like to kick, and then mimic with my left.
I'd also watch left handed people do stuff, its wierd, cause their movement, Like bowling(cricket) is at a totally different angle to right handers. It did help my best friend is left handed.
Lessons & tips: Just practice, cause even though its frustrating, you eventually get the movement fluid. Like a baby learning to walk. And the more you do it, the easier it becomes with different things.