R12 Project accounting, budget type in Budget screen

Question: Can we delete the budget type of a project or can we change the budget entry method of that budget type with different categorized BEM.

EX: I have project A which is not baseline budget, assigned Forecast cost budget by adding Budget entry method(conversion_budget) which is not categorized.

1. Here I would like change the BEM(conversion_budget) to custom BEM(Like say Jacobs_SOHO) which is categorized.

                                                                                 OR

2. If not possible above solution, would like to delete the Budget type Forecast Cost budget and add new budget type to that project A

Please advise.

Thanks,

Suresh.