The replacement-or just reinstallation-of inserts isn't rocket science but there are a couple of special tools that you won't have and perhaps don't want to buy. Extracts from B&S manual follow. To Drive In New Valve Seat Insert Select the proper valve seat insert and the correct pilot and driver according to Table 3 & 4. You will note that one side of the seat insert is chamfered at the outer edge. This side should go down into the cylinder. Insert the pilot into the valve guide. Then drive the valve insert into place with the driver, as shown in Fig. 17. The seat should then be ground lightly and the valves and seats lapped lightly with grinding compound. Clean thoroughly. NOTE: Aluminum alloy cylinder models. Use the old insert as a spacer between the driver and the new insert. Drive new insert until it bottoms. Top of insert will be slightly below cylinder head gasket surface. Then peen around the insert as shown in Fig. 18. NOTE: Replace Cylinder if a .005" (0.13 mm) Feeler Gauge enters between Valve Seat and Cylinder.
