How to purify oneself prior to offering prayers!

Verse 6 of Chapter 5:

O Believers, when you rise to offer the Salat, you must wash your faces and hands and arms up to the elbows and wipe your heads with wet hands and wash your feet up to the ankles; and if you have become unclean, cleanse yourselves with a full bath; if, however, you are sick or are on a journey, or if any of you has relieved himself or if you have "touched" women and you can find no water, then cleanse yourselves with pure dust: strike your palms on it and wipe your hands and faces with it. Allah does not will to make life hard for you, but He wills to purify you and complete His blessing upon you so that you may show gratitude.