Yes - - it can be done, however for the expense and work involved, you would in most cases be further ahead to fis the problem you have & trade it in on what you want. It could also be cheaper to just go & buy a comparable vehicle that is already an automatic & just sell the one you have for parts or whatever.
Sure you can, but as far as the cost to do the swap, you would be better off finding an automatic truck and buy it. It will cost more than $600 to do the swap, if you can find the parts used.