As far as I understand your question, the devicetool file is where you left it. If you are at the end of the process, then you have already modified the file. Where was it when you did this? You seem to refer to two files. What is tp_activate(1).zip? Is this the modified version? I'm not sure it will run under java unless it is a .jar file (this maybe as simple as changing the suffix)
I don't know what system is running on your computer, but you could search for the file name and then look at it's properties to see the path. On a windows machine, this is typically by right clicking on the file icon and selecting 'properties'. If your system has an address bar in it's windows, the the path is displayed there.
If you have downloaded the device tool and not moved it, then it is in the folder where your browser downloads items. This is set in the browser preferences or options. I think the default is 'downloads'.
A typical path might look like this (on windows):
C:\Documents and Settings\your_username\My Documents\Downloads\devicetool2.jar
This thread: HP TP Server Error
Also has instructions for this process (derived from the ones on this thread). They start at post 13. Post 20 is a user asking about the path. You can see from the replies that it seems the path you type should be relative to your position in the file system (post 25