The ritual described in the scroll uses the scroll as a material component. It takes a full hour to cast, and requires three successful DC 20 skill checks. Each PC can attempt a single skill check during the ritual. Acceptable skills for the check are Knowledge (arcana, planes, or religion), Linguistics, Perform (oratory), Spellcraft, and Use Magic Device. Expending an ability that releases positive energy, such as cure spells and channeling, grants a bonus on a single check. For spells, the bonus is equal to the spell level; for channeled positive energy, the bonus is equal to the number of dice rolled. Every 5 points by which a character exceeds the check's DC, the PCs earn an additional success. So in theory one PC could crush a roll and do it by themselves.
