Assuming he gets basic knowledge, he blitzes super-scientists/mages before fighting any bricks.
Which poses a problem: Surfer will probably notice the instant Reed dies. He has the reflexes to reach Supes before he hurts anyone else. Then it's CIS-less Supes vs Surfer which, at the very least, should last long enough for some high-end mutant psychics to shut down his mind.
Marvel Earth is hard to solo unless you're willing to destroy the whole planet.
Well since speedblitz are allowed and he is the juggaman I'll have to use scientific physics+logic=juggaman uses Sppeedforce Blitz thourgh all the marvel universe headshots and bodies which is Speed x force of impact+invincable= domino's effect causing all marvel to fall down one by one. also as speed increase the force blow the opposing ends receiving the blow disintigrate due to the speed increasing the force and energy/heat output.