On C drive there should be a file called ind-bios.cfg if you use FTP to copy to a PC you can edit it and then replace it back on the Xbox.
Right down the bottom of that file you will see 4 lines of text like this.
"DASH1=\Device\Harddisk0\Partition2\evoxdash.xbe"
"DASH2=\Device\Harddisk0\Partition1\Dash\UnleashX\unleashx.xbe"
"DASH3=\Device\Harddisk0\Partition1\Dash\EvolutionX\evoxdash.xbe"
"DEFAULTXBE=\Device\CdRom0\default.xbe"
Edit it to this as this will set the 1st boot dash to xbmc on E drive,
DASH1=\Device\Harddisk0\Partition1\xbmc\default.xbe
DASH2=\Device\Harddisk0\Partition2\evoxdash.xbe
DASH3=\Device\Harddisk0\Partition1\Dash\UnleashX\unleashx.xbe
DEFAULTXBE=\Device\CdRom0\default.xbe
If you have xbmc4gamers in E:\xbmc4gamers the make DASH1
DASH1=\Device\Harddisk0\Partition1\xbmc4gamers\default.xbe
The X2-5035.67 bios is a 512kb size that will only flash to a version 1.0 - 1.1 TSOP or some mod chips and the configuration file should be on E drive root directory
Download FatXplorer
https://fatxplorer.eaton-works.com/3-0-beta/
Then you can connect your HDD to your PC and using Fatxplorer read/write as if it was a normal PC drive.
Cheers
SS Dave
Soft modding is like masturbating, It gets the job done but it's nothing like the real thing.