First, use the VMWare command*:
C:\Program Files (x86)\VMWare\VMWare Workstation\vmware-vdiskmanager -x 32Gb "x:\Dir\DiskFileName.vmdk"
Or where ever your VMWare workstation is installed
This will increase it to 32gb
Then go to http://www.partition-tool.com/personal.htm and you can use their free version to increase the primary drive.
the free version only supports 32bit OS, so if your vm is 64, you might look at mounting the linux iso at www.sysresccd.org to increase the partition.
Hope that helps.
* one thing to note, I read somewhere that you should not have any snapshots of the drive sitting out there. Also, back everything up first before trying (I made full clones, just in case).