You can use VMware vCenter Converter to shrink your virtual disks, see the following VMware KB article: Growing, thinning, and shrinking virtual disks for VMware ESX and ESXi (1002019) | VMware KB
Virtual disk shrinking is supported when using VMware Converter converting source virtual machine as a machine source (not as virtual to virtual).
Note: You cannot shrink virtual disks using vmkfstools in ESXi as the hypervisor is not aware of the file system layout and cannot ensure a safe shrink operation.
Migrate the data away from the end of the disk consume to ensure the data is not lost (because the disk area is effectively removed). For example, in Windows GuestOS use derangement tool.
Shrink the partition residing within a disk before reducing the size of a virtual disk.
Non operating system disks users can also add a new smaller VMDK to the virtual machine and copy the data between the larger and new smaller disk using tools within the guest such as Robocopy.
When you delete data from a thin-provisioned .vmdk, space is not reclaimed back to the datastore automatically. Similarly, when you delete a .vmdk or a whole VM from a datastore, space is not reclaimed back to the storage array automatically either.
In the first case you will need to use VMware Converter and run a V2V conversion (make sure you have enough space on the datastore for the cloned VM). In the second case you will need to run a manual UNMAP operation. You can find more information on how to do this in the following KB article: https://kb.vmware.com/kb/2057513.