Use a paint brush and Circa antique furniture stripper (this will not remove any markings on the stock) and wipe it off with fine steel wool. Then depending on if it is laminated or hardwood, you can use a 5% iodine solution to bring out the grain or colour, then rub the entire stock down with natural bee's wax.
Do not use boiled linseed oil to refinish a k98k stock.
PM me if you want the complete instructions.