The freebsd-update(8) utility supports binary upgrades of i386 and amd64 systems running earlier FreeBSD releases. Systems running 8.[4]-RELEASE, 9.[123]-RELEASE, 10.0-RELEASE, 10.1-RC[1234] can upgrade as follows:
# freebsd-update fetch
# freebsd-update install
2.1. Upgrading from Source
Follow the proper instructions (see section 2.2.) to upgrade to FreeBSD 10.1.