This is extraordinarily similar to what I helped you with before. See this particular post
to refresh your memory.
What we have is a series of "PPU strings". In the case of the word "END", look at 0x17CEA. You'll see 21 ED 03 DE E7 DD. The format is AA BB LL (BYTES), where AABB is the PPU address data is written to, and LL is the length (number of bytes) to write to the PPU, with the actual data following. In this case, the address is 21ED, the length is 3, and the data is DE E7 DD (which are the tiles for "E", "N", and "D" respectively). The address basically says where on the screen the text or graphics will appear. If there's any part of that you don't understand, I'll be glad to go into more detail.
Now, the thing is there is a whole bunch of these "PPU strings" stuck together. The game has a pointer to the first
PPU string in the group. When the game draws to the screen, it does a whole group each frame, stepping through the PPU strings one at a time until in reaches the end (it looks like the end is marked with an FF in this game). What this means is that the game doesn't have a pointer to every piece of text, which means you can't re-point just a single piece of text. You have to re-point a whole group.
Start by working your way back from the "END" PPU string, until you reach the beginning of the group. For example, just scanning through in a hex editor, I can pick out the previous PPU string: 20 66 14 F4 EB DE E0 E2 EC ED DE EB F4 F2 E8 EE EB F4 E7 DA E6 DE F4 (at 0x17CD3). Eventually you should work your way back to the beginning, where you will probably find a preceding FF that terminates the previous group.
Then work your way forward. You know where the "END" PPU string ends, so you can find the next one. And it tells you what its length is, so you know where to find the next one. Keep working through until you find the FF that terminates the group.
Now you know where the group begins and ends. Figure out what the address is of the beginning of the group, and find it in the ROM. Then, find a nice patch of FFs (there's one nearby). Copy the whole group, and update the pointer to the group. Now you can expand any text within the group without worrying about pointers anymore.