Yes, this is the good link, and no you don't have to change the sim socket on DM motherboard, you have nothing to do, just replacing the sim (doing as explained in the Tutorial), as you would replace the sim in a mobile phone,

TS
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DM8000, DM800se, DM500HD, DM800HD, DM7025, DM7020s, DM7000, DM500s
VU+ Solo, VU+ Uno, VU+ Duo, Kathrein UFS910
Tivusat, TNTSat, Fransat, SSR/TSR, BBC1-2-3/ITV
DE-OpenBlackHole 1.4 image : http://www.openblackhole.com/