If you have a harddrive, use that instead.
I've laid out some rough instructions here, I may have made some mistakes because I'm not in front of an amiga at the moment, but this should be a good start.
Create a drawer on your harddrive, call it instruments:
Double click on your harddrive from the workbench
use right mouse button, select new drawer, enter name.
lets say the new folder is now on drive dh0: named instruments.
Download and transfer all the lha files to your amiga:
If you dont have the LHA program itself, you'll need to download that too.
save the lha files in the instruments folder for now also
Follow the instructions to install LHA:
(if i recall correctly)
Double click on your harddrive from the workbench
double click your instruments folder
right-click select show-->all files
double-click lha.run to auto-extract
leave the instruments window open, and bring the harrdive window to foreground.
right-click select show-->all files on the drive window also.
Double click the "C" folder.
Drag "LHA" from instruments drawer to C: drawer
Close C: window
Now open a shell:
Right click on the workbench screen, select "execute command" from the top menu.
Type "newcli"
type "cd dh0:instruments"
Now extract all your lha files:
lha x st-16.lha (substitute the name of the lha file you want to extract)
Do this for all lha files.
Now make an assign to point to these files:
in the same shell, type "ed s:startup-sequence"
scroll down the file until you see the other assigns
add a new line after the other assigns that looks like this:
Assign >NIL: ST-16: Dh0:Instruments
create a new line for each assign you need
when finished press escape, then press x then hit enter
Now reboot your machine and give it a shot.