Touch off and tool change (noob!)

I have LinuxCNC set up for my machine.
I have a gcode program ready to go.
In axis I touch off all three axes to zero at the bottom left top corner of where the 'thing' should be made.
Then I run the gcode but it complains that the program exceeds the machine coordinates at the next tool change (manual).
I think this is because it is adding X300 to the touch off X value which is more than the maximum X value (300).
How do I turn off the touch off offset so I can move to the tool change position, change the tool, and then switch the original offsets back on again to continue machining?

There is no way to turn off the G54-G59.3 coordinate systems.
How ever are a couple of ways you might do this.
Probably the best way is to use a G53 command. It allows for a positioning move using the machine coordinates (no offsets...). The downside to using this command is that it is only active for one line of code.
Another option would be to have a coordinate system set up with zero offsets and engage that system with a G54-G59.3 command. The downside to this method you have to be certain that no other offsets (G92 or tool offsets get in the way.)

G53 sounds like it will do what I want. Now off to try it...