Any school can solo the dungeon, although Life might struggle due to the lack of an AoE. You might want to buy some Forest Lord or Forest Lord Cub TCs in the Bazaar. Use those and Centaur for attacking, pack some Satyrs and maybe a Rebirth for healing, some Tower Shields if you have it, Lifeblades and Spirit Blade from Krokotopia. If all else fails, use Team Up or find a team on a fansite.
is there any way for a life wiz to solo the last dungeon in dragonspyre if not what do i do for help
I soloed with my Life wizard (and Death and Ice as well) but used henchmen I think twice in the entire dungeon with her. Just make sure you are level 48+ and have the best gear possible. Look up the dungeon on Wizard Central to give yourself a heads up on the NPCs and their possible spells. And mark your spot occasionally so you can port out and back in (refilling life/mana).