Device: Samsung Galaxy S4
Android: 4.2.2
I can't get into Download mode. I have tried many options like removing battery solution, pressing Vol Down+Home+Power. I always get into Recovery mode.
That's it, now you can connect your device with your PC after you launch ODIN.
You can try adb reboot bootloader
from PC if the above doesn't work.
You can do it the easy way: Download ROM Toolbox. Then choose reboot to download mode.. :) good luck