Typically it's very easy...

Local business license (pay fee)
State LCC Paperwork (pay fee)
Transfer ownership (and maybe pay tax on the value).

However...if you want it to actually protect you, you may need do some other things to ensure that it looks like a legit business: Business documents, business plan, annual shareholders (owners meeting), separate bank account (and credit card if you use one), loan documents, etc.

The state will happily take your fees and give you an LLC, but if a plaintiff's attorney can show that the LLC was not really operated strictly like a business then he can pierce the veil at trail and get at your personal assets. You may or may not need a reasonable business plan with a reasonable chance to make money...depends on the state.

Bottom line, see a lawyer.