Decrypt document and data group

I am pretty new to openssl and x509, and this was part of an exercise; hence with my limited knowledge this question might not make all the sense.

I am provided with a X509 certificate, along with some data group and documents, which have been encrypted with the certificate.

Is it possible to read those documents and data groups using openssl?

I was able to find some links: http://ift.tt/1vfflIL on it, but not sure how to use this or if this is even a correct approach.

Also a tool: xcarecrows. Is there any way I could do this using openssl on command line?

Here are my files (certificates, documents and data groups.)