Try it.
Take a coin with good sharp features and place a sheet of paper over it.
Experiment with pressure, rubbing and striking with soft objects.
I tried this with a half dollar and some other large coins. It actually works pretty well. You have to be careful around the edge if the coin edge is sharp. But with a little practice you can get some pretty good results.
If a person has something resembling a press in their home (a bottle capper, garlic press or even long jawed pliers) they could probably get more consistent results.
I tried it with high quality 25% cotton fiber paper and a quarter and did not get anything resembling an embossed seal.
It would be much easier to just download image from Web and use Photoshop to create an emboss feature. Also it is not clear how the alleged forger would have obtained a Kenyan 2 shilling coin.