It's inevitable that, over time, your paver patio or garden stepping stones will sink into the ground; depending on the process and materials used to install the pavers, this could take months or it could take many years. Pavers sink due to the settling of the ground; the wetter your area, the faster the pavers will sink. Fixing sunken pavers is a fairly straightforward task and can be completed in a weekend.
Remove the old pavers. Wedge a crowbar under each paver and pry it out. If you are removing all of the pavers from a patio, note the size of the joint (gap) between pavers, then remove and lay the pavers out in the same order nearby so you can replace them quickly.
Level the ground beneath the pavers with a bow rake. Firmly compact the area with the tamper. Hold the tamper in front of you with both hands around the handle and tamp an area until the ground is hard; move to another section and repeat until the whole area has been compacted.
Spread 2 inches of crushed limestone over the area, level with the bow rake and compact firmly with the tamper. Spread 2 more inches of crushed limestone, level and compact.
Spread 1 to 2 inches of sand over the limestone and level with the back edge of the bow rake. Compact with the tamper.
Lay your pavers. Check each for level, and keep the joints consistent with the original layout.
Spread masonry sand across the patio. Sweep the sand into the joints and tamp gently with the tamper to allow the sand to settle. Continue adding, sweeping and tamping sand until your joints are full.