Well that looks like easy;
As you removed the scsi card I presume you have no scsi devices in your PC.

So there's only one device, namely the scsi cd-rom in your akai sampler.

The only thing you have to worry about is that the controller in your sampler is not on same ID as the tekram controller in your pc. and ofcourse the cd-rom has another ID as both controllers.

I never owned a Tekram, but I looked at their website and apparantly these cards come with a pci utility for setup, which probably will also install the aspi layers needed for windows O/S systems.

step one.
So first to do if you did not already;
Install card (do not connect yet the sampler)
Use the pci utility to find on which ID the card is! (probably on ID 6 - last in 1rst chain for autotermination.)

Configure your sampler;
1. If possible set controller on ID 5
2. set cd-rom on ID 1 or 2 or 3 or 4..!

When done you can connect safely.
Allways keep in mind that whenever you add any other scsi device, first look at the ID's , set the new device on a FREE ID first, before connecting.

Step 2
Boot both systems where I suggest sampler first.
Cheque or your tekram card finds the cd-rom and the akai controller..
If ok, your hardware is set up wright.

Step 3
For transfering roland(xp50) files you probably need software which is able to read roland files.
Windows cannot read roland format by itselve.
I suggest wavelab as you do use cubase and wavelab comes from steinberg as well.

Good luck,

Fred

Note;
Just in case the sampler devices are not detected by the tekram card, try rebooting in reverse order..pc first and then sampler.
I don't know or the tekram cards have their own bios or that they depend on windows O/s.