John Hayes was given a well earned rest last time out as Munster qualified for the Magners League semi-finals thanks to the losing bonus point they picked up against the Blues.
Earls' return to the Munster team sees Lifeimi Mafi switch to the left wing, while Denis Hurley makes way for Howlett on the right.
Tom Gleeson loses out in a rejigged back-line which also includes switches at full-back and scrum half - Paul Warwick starts in place of Scott Deasy and Peter Stringer makes way for Tomas O'Leary.
In the front row Damien Varley continues at hooker as Flannery returns from injury to provide back-up on the bench, and Hayes takes over from Tony Buckley at tighthead prop.
The fit-again O'Driscoll joins Donncha O'Callaghan in the second row, and Alan Quinlan returns at blindside flanker, alongside Niall Ronan and Nick Williams, who takes over from David Wallace at number 8, in a powerful back row.
Wallace and James Coughlan will be hoping to make an impact as replacements as Munster look to end a three-match losing streak against Leinster and progress to the inaugural Magners League grand final.
Speaking ahead of Saturday's game, Munster coach Tony McGahan said: "It's been an okay season, but the real goal for us is to finish with silverware and we have to give ourselves every opportunity with a tough 80 minutes on Saturday.
"We haven't shied away from the fact that we have been inconsistent this particular season. We've had some excellent days out but, at the same time, we've certainly let ourselves down with inconsistency right across the park.
"It hasn't been limited to one or two areas - it's been set piece perspective, it's been attack, it's been defence, it's been the breakdown, it's been goal-kicking, it's been field-kicking. We haven't really been able to gel everything together.
"We've reached a semi-final in the Heineken Cup, we're into a semi-final in the Magners League, and we've got a final with the 'A' team at the weekend. I think in last Sunday's game in Cardiff - even though we didn't win - we had done enough to get the result and that has certainly given the squad a big boost."
He added: "Heading into a semi-final in Dublin, there is plenty to be pleased about and we are certainly looking forward to that aspect of it.
"I think the kicking game is going to be a huge part of the weekend.. Leinster certainly demonstrated over the last number of years and especially so in this particular year, their physicality in their carrying and the physicality in their defence. So that's going to be another key area for us."
MUNSTER (v Leinster): Paul Warwick; Doug Howlett, Keith Earls, Jean de Villiers, Lifeimi Mafi; Ronan O'Gara (capt), Tomas O'Leary; Marcus Horan, Damien Varley, John Hayes, Donncha O'Callaghan, Mick O'Driscoll, Alan Quinlan, Niall Ronan, Nick Williams.
Replacements: Jerry Flannery, Dave Ryan, James Coughlan, David Wallace, Peter Stringer, Denis Hurley, Scott Deasy.