Measure the outline of the of the stoop. Cut the 2-by-4 boards to match the measurements of the perimeter. Build a frame out of the 2-by-4 boards by attaching them with the drill and screws. Place the frame on the stoop and hold it in place by inserting wooden stakes into the ground around it.
Mix together a solution of three parts sand to one part concrete in the bucket. Add water to your mixture and combine until it is the consistency of thick mud.
Pour enough concrete into the frame for one stone. Place the paver stone into the concrete and press down to embed it into the concrete. Repeat this process, laying down concrete and placing stones until all stones have been placed. Allow 24 hours to dry.
Mix together one part sand and one part concrete for the grout mixture. Add enough water to create a mud-like consistency. Place the mixture in a grout bag. Cut out one corner of the bag to form a spout.
Fill in the gaps between the paver stones with the grout mixture. Fill all cracks completely. Wipe away any excess grout with a rag. Allow 24 hours to dry.
Remove the wooden frame from the paver stones you laid.