Unable to delete a sheet - poss corrupted.

I pasted and copied a document including some graphs into a new sheet on my main spreadsheet. Since then I have updated to the latest version of libreoffice and also had a virus slip through called " fat obfuscated " I think AVG has dealt with the virus now including doing a full scan while in safe mode.
My problem now is if I open the sheet that I psted and copied into, the graphs are corrupted and libre office responds to any commands by going really slow and the " not responding " error message flashes on and off at the top of the screen. MAybe the file is massive ??? I have tried deleting the sheet using the edit command, also clicking on the tab with no joy. As it goes away to delete he sheet it crashes libreoffice and recovers the document next time I open it.
Everything else appears fine on my win 764 bit pc, including all the other sheets I use in libreoffice.
Is there a way to delete that sheet without opening the program ???

Any help or thoughts appreciated.
p.s. I also restored to the previous version of libreoffice.

Close the office completely (mind any running quick-starter in the tray).
Rename your user folder %APPDATA%\OpenOffice\4\user to something else, say Xuser.
Restart the office. It will assume a first start and creates a new user profile. Test your spreadsheet again.