Yup , that big syringe should do.
Bleeder on fuel filter looks like a brake bleeder nipple and should be located on top of the housing you screw the filter cartridge into.
To look up names of unknown parts you can use the parts diagrams provided by partsouq.com or amayama.com .
Good luck Ralf
Welcome to the madness 😁
Do you have workshop manuals (including wiring diagrams) for your rig? If not: Get some.
Check here:
https://forum.ih8mud.com/threads/online-repair-manual-sources.185322/
You say the manual priming pump is not hard? Then there is air in the fuel line. More likely than...