Okay, here's an easy tutorial, you need:
1. YSMenu Generator for R4/M3Simply/Clones 1.5.1
http://gbatemp.net/index.php?download=7244
2. ysmenu
http://yasu.rank.nu/yasu/count.cgi?n=YSMEN...u0903270000.zip
3. copy of the latest dstt kernel
http://gbatemp.net/index.php?download=7377
4. copy of DLDI No-AutoPatch
http://dldi.drunkencoders.com/uploads/c/cd/Dldino-apatch.zip
5. A working R4i-SDHC (1.4) with latest firmware (O RLY??)
here's how you do it:
1. Launch the generator and create ysmenu by following the instructions, choose media replacement as boot type.
You'll find the new created ysmenu files in a "generatedxxxxxxxxx"-folder inside the ysmenu-generator folder.
2. delete the r4dldi.dat and the r4patch.dat inside of TTMENU-folder
3. extract YSMenu0903270000.zip and [7377]TTMenu_V1.17a07.zip
4. copy the ttmenu.dat from [7377]TTMenu_V1.17a07.zip into the YSMenu0903270000-folder, run ttextract.exe
5. copy the newly created ttdldi.dat and ttpatch.dat into your "generatedxxxxxxxxx\TTMENU"-folder
6. extract Dldino-apatch.zip, run DLDI No-Patch.exe, point to the _DS_MSHL.NDS and apply the patch.
7. copy the content of ""generatedxxxxxxxxx"-folder into the root directory of your r4i
8. edit r4imenu/multimedia_path.ini with notepad and point to /_DS_MSHL.NDS
you should now be able to run ysmenu from the multimedia-button in your r4-menu.
soft-reset and "back to firmware" doesn't work for me, but that's... negligible....
and btw., i'm a total flashcard-newbie myself, i figured this all out by READING!!! (thanks to gbatemp, great website), searching (google ftw) and trial&error
i'm so proud of myself...
edit2: softreset works, just rename the _DS_MSHL.NDS to ttmenu.dat... and dont forget to edit your multimedia_path.ini