One day, one hour, one minute, one moment at a time. That's how to do it. Oh, and don't get mad when you can't do it; just try, try, try again until you do. This is one of the biggest and most important lessons I have learned these last few years while adjusting my life to the new conditions and limitations dictated by my chronic illness. The other one is to focus on the good, not the bad. Focus on the good things, not the bad, the loss, the struggle, the suffering. Always focus on the good, and if you can't find anything good around you, then keep looking until you do.
Never give up. Never surrender.