Prestashop website modifications

I want to make different modifications in a prestashop website, here is the list of all the modification that needs to be made. The modifications needs to be made within the next 24 hours. I want Guaranteed success. Thanks. - Change a payment method (just change text in panel, and in bill for client) from Cash on delivery (COD) to Paiement au showroom. Check and make necessary changes - For all clients under 250.- spent then 12.50 with "la poste" above is free, and always free if store pickup (Retrait en magasin). (make sure logged in, and not logged in works, make test account if necessary) - Hide prices to client unless logged in. - Remove a section in main page -BUG: When adding a product it adds 2 even though only put one in quantities. -make sure all products are set to advanced stocks -put 7.8% taxes ( prices in panel are already tax included) Those are the only things needed to be done only bid if you know how to make these changes thanks.