If you send a complete standard(not free float/rail/MLOK, etc) upper which needs to be disassembled and then reassembled, a handguard/rail system installed, you need to select this service. This service does not include installation of new/swapped FSBs onto undrilled barrels. If your upper has a pinned/welded muzzle device you need to add that service which will destroy the device. We do not remove pressed-in/pinned barrels as used in HKs and AKs etc.. We will NOT attempt to install or remove any Chinese parts. If you are sending an upper with a handguard other than standard plastic/delta ring kit, you must select the Freefloat/rail service linked to below. We DO NOT take apart and reassemble LWRC uppers.