You can create a Sierra USB installer using the usual manual process (same as for Yosemite or El Capitan), then install the bootloader (Clover or Enoch) and the required bootpack. You can reuse your existing Yosemite pack (I understand you currently run that). For an Enoch based installation with BIOS in legacy mode, you can follow a similar process as described, excluding the computer's specific pack of course.

Hi, i have a Dell XPS L502x running OS X Lion 10.7.4 and i got the Dell Wireless 1701 802.11 b/g/n from my brother's Inspiron N5050. I installed Atheros AR5B95 kext using Kext Wizard, repaired permissons, rebuild cache, restart but the kext doesn't seam to load. Aug 24, 2011 - An Intel-based Mac that supports Mac OS X v10.7 Lion. A Mac OS X v 10.6 Snow Leopard installation disc. Are different here in the UK, but I have just bought an XPS L502x for less than 44% of the equivalent MacBook. Kalvisolai.

I would recommend you create a separate partition and retain Yosemite for the time being. Avtozhir svoimi rukami chertezhi.