What does E9338 look like? (The Ford tool for removing timing chain tensioner)

Looks like a long shaft 3mm allen key with a piece of garden hose over 3/4 the length of the shaft.

is it worth getting? wat does it cost?

I just told you how to make it. Dont buy the genuine tool, they are expensive and not worth it.

To undo the tensioner, remove the centre cap (14mm bolt) without removing the body it is bolted into (hold it with vicegrips or something). Once the cap is removed, you can fit a long shaft 3mm allen key into the centre of the tensioner - feel around, the hole is there - turn it clockwise to lock it and the chain will become slack.

arm is right, done it that way on mine a few times.