Need to replace Shimano chainwheel

[Octalink]

Does anybody know if Shimano FC-CT90 chainwheel is taper square or octalink?

 

[Gunk]

That looks like square taper, easy to remove, you’ll just need an extraction tool.

 

[iluvmybike]

Defo square taper - 14mm box wrench to remove the crank bolt then standard crank puller