Selling home under new tax break

I have a tenant who will be a first time home buyer, wants to buy the mobile home they are living in in a park (so no land) under the tax credit program that is about to run out. Good tenants, they need the tax break too, neither I nor they can get any good information on how to structure it so that it qualifies for the break. This is in Alabama and the tax people at H & R block in that town had no idea of the program. They contacted an attorney who for a fee they can’t afford will look up the rules for them?

Any one done this and know how to do it correctly, what forms to use etc?

THanks in advance