The full concept art for Alistair can be seen at official page: dragonage bioware com/characters/alistair
Retouched: nose, chin and the jawline, cheek shape, placement and prominence of the cheekbones. Other features kept more or less the same.
installation: use DAupdater.exe (found in ../bin_ship sub-folder of your Dragon Age installation folder.
to uninstall: go to folder../BioWare/Dragon Age/AddIns typically located in your Documents folder, and delete sub-folder there named "tmp7704_alistair". Then go to ../BioWare/Dragon Age/packages/core/data folder and do the same with .erf file located there, named "tmp7704_alistair_package"
(the *.mrh file contained in "concept_alistair_mrh" archive is optional and only useful as source for the DA Toolset, if someone wished to use this modification as base for their own)
modders can use this for their mods. credit my name if you please