The front row welcomes back team captain Rory Best who returns from injury to line up beside Bryan Young at loosehead and tighthead Tom Court.
Stephen Ferris also returns to action with Roger Wilson dropping out of squad and Neil Best named as back row cover on the replacements bench.
In the backs, Williams has made three changes with the half-back partnership of Isaac Boss and Paddy Wallace replacing Paul Marshall and Niall O'Connor.
Bryn Cunningham returns to start at full-back with youngster Mark McCrea named on the bench.
Williams is hoping that the 'Fortress Ravenhill' mentality will return to Ravenhill for the final three fixtures which will prove crucial for his side's chances of playing in the Heineken Cup next season.
Connacht are close behind Ulster with only four points separating the two provinces, and with Connacht having two home games left to play at the Sportsground, Ulster's qualification for the Heineken Cup is by no means secured.
ULSTER (v Munster): Bryn Cunningham; Tommy Bowe, Andrew Trimble, Rob Dewey, Mark Bartholomeusz; Paddy Wallace, Isaac Boss; Bryan Young, Rory Best (capt), Tom Court, Carlo Del Fava, Ryan Caldwell, Matt McCullough, Kieron Dawson, Stephen Ferris.
Replacements: Nigel Brady, Justin Fitzpatrick, Justin Harrison, Neil Best, Paul Marshall, Niall O'Connor, Mark McCrea.