Seam sealer fail - help

Thanks for all the tips. So I settled on 3M 08307, 2 tubes, and 1 gun. So as I wait for delivery, I am concerned how to tool this stuff, if possible. Dry time? Like as it gets down to below the windshield area, it needs to swoop up and then under hood. Not sure how a self leveling product is going to go up? So can I spread it with finger?
Since it is self leveling it will be pretty fluid. Put tape on the bottoms of the drip rails to keep it from running out. Also make dams with tape
to contain it where you don't want it to go. Self leveling means it will self level. On the flat areas of the drip rails, you won't need to
tape it or smooth it with your finger. As with all body work patience is key.