Hello, On a T4A slip I have Box 107. ( I have entered after Tips an amount that now shows on my return after box 107 "less: contributions ... How do I remove this entry?

When using TurboTax Standard, click on Find in the top right-hand corner, type Tips, gratuities or occasional earning not reported on a tax slip from the payer, select it and click Go.  You will then be able to remove this entry from your tax return.