I need help! 78 yamaha xs400 first bike problems!

[Juju400]

Broken spark plug in cylinder head. How can I get this out? It's really bugging me that this is keeping me from making progress on the bike. I've been reading I same that using penetrating oil might work or heating it up and then cooling it down might work? Advice please. I want to have this bike running in a month and I'm way behind .

 

[CDNTX650]

I removed the head so i could grab it from the inside .

 

[Juju400]

is that difficult to do?