Assuming your loan is HAFA-eligible, or otherwise eligible for getting pre-approval on a sales price, the most important thing will be to try to get the BPO to come in at a low enough number to entice/enable your renters to buy it. If it's a drive-by BPO, this may be impossible. It it's an interior BPO, then you will get notification and have some opportunity to intercede with the BPO agent with your list of low comps or other supporting information of the "negatives" with the house and neighborhood, to nicely encourage them to come in with a lower number.
Most times, the listing agent would play this role of trying to intercede with the BPO agent, and since you live out of the area it may be worth it to use a savvy local short sale agent. Plus, if the BPO comes in too high, the SS agent knows how to most effectively appeal the amount. You can call a large realty office and ask for their most experienced short sale agent. Your renter would put in an immediate bid to "pend" the property when it's listed. Your renter will need to be pre-approved by a lender as well, prior to them even submitting the offer.