According to the screenshot, the VM has two snapshots, but it's running on the first one and the second one is currently unused. Anyway, if you want to get rid of the snapshots, just run "Delete All" which will merge the data of the currently active snapshot to the base disk.
Like André said, just click "Delete All" and all snapshots will be deleted... and VMware recommends no maintain a snapshot for more than 24-72 hours.
Ok...thanks for the answer, but it gives me more questions, because the snapshots are almost more than 1 year old and are about 15GB.
Don´t know how long it will take to "Delete ALL". (Its far over the recomedation time).
Is it a better idea to convert the vm into another one, I don´t know if the converter let me do it.
What more possibiliteis do I have?
How long it will take to complete depends of VM activity and your disk subsystem, but remember that the VM will continue online while the snapshots are deleted... and if you can Power Off the VM, the snapshot removal will be faster.
And about convert the VM into another, this may will take more time than remove the snapshots.