I've done similar things for German.
The best way I've done is to convert the symbols first by using an on-line translator and doing a search and replace. Perhaps concentrate on the I/O first.
You can convert the program into a source code, and do a similar thing there and recompile after, but I would complete the symbols list first because if you change what is a symbol then you'll have problems re-compiling.
It a long way to do it, but I don't know of any auto software. Using on-line translators also means you have to think about some of the translations. For example, recently the translator came up with 'intruders', it took me a while, but finally realised it meant 'inductors'.