From my 401k and do a rollover with the remaining amount. Or will I have to do either a 100% rollover or 100% withdrawal.

If you "separated from service" from your employer in the calendar year in which you turn age 55 or older then you may take withdrawals from the 401(k) plan that was sponsored by that employer without penalty (though you will pay federal and possibly state income tax on the amount you withdraw). The withdrawal can be partial, or full - there are no rules about that. This assumes that you have more than a small amount in the plan - some employers require ex-employees to take 100% withdrawal if they have less than $5K balance in the plan.

Please note - if you still have an old 401(k) plan with an employer you left prior to turning age 55 you cannot take a withdrawal from that account without penalty until you reach age 59-1/2.

Once you have taken the withdrawal you may then decide to move the remaining amount to a rollover IRA. If you do it properly there are no immediate taxes or penalties for making the rollover.