There are a few bus services, the 885 would probably help you.
From KES website:
The school is situated near many bus routes (the 61, 62, 63 and 144 buses stop within 200 yards of the school) and it is within easy walking distance of the University railway station. The School has dedicated Travel West Midland buses 885 and 886 (shared with King Edward VI High School for Girls) from Solihull and Walsall. KEHS parents run a bus from Stourbridge. If this service may be of interest, please ask us.http://www.kes.org.uk/885-solihull-bus-service.html