what kind of kalashnikov do you own?
you probably need to remove the front sight base and the gas block (ak47 and akm). then replace the gas block with a new one of the correct diameter to fit your bbl.
obiously, you will need a hammer and a nail set to start the 3mm cross pins moving. you wil also need a 3/32" drift punch to drive the pins out after you started them moving.
you will also need access to a hydraulic or arbor press to slide the front sight base and gas block off of the bbl.
an ak74 simply needs the fsb replaced.