how can i do it

Easy.

First, it is better to create a new VIEW for this, rather than changing one of the built-in VIEWs.



% Work Remaining = 100 - % Work Complete



Use a spare Number field/column, such as Number1, to do the calculation (Tools, Customise, Fields).



Number1 = 100-[% Work Complete]



Then use a formula in a spare Text field/column (Text1, Text2) to include the "%" sign and some title text for the display:



Text1 = [% Work Complete] & " % WORK COMPLETE"

Text2 = [Number1] & " % WORK REMAINING"



For convenience, rename Text1 and Text2



Text1: PERCENT WORK COMPLETE

Text2: PERCENT WORK REMAINING



Then use Format, Bar Styles, Text (tab) to show Text1 and Text2 on the ends of the bars.