Do you mean the temp files? You would need to do a search for "Photoshop Temp" and then delete the files. Ex. Photoshop Temp2777286510092

Also, I want to get rid of the partition. Do I have to format my 256 SSD and reinstall Windows 8?
Which partition are you talking about? If you have a C: and D: partition, then you can just delete the D: partition and expand the C: partition.
http://www.howtogeek.com/howto/windo...windows-vista/
You could also use a third party tool like MiniTool:
http://www.partitionwizard.com/free-...n-manager.html