KarL-
Since your using a bin file, you can use the following command;
copy tftp:///c2950-i6k2l2q4-mz.121-22.EA7.bin flash:
This will probably erase flash first (it will only if there is not enough room for both images), then copy the image over. Don't forget to reload to 'load' the image.
HTH and please rate.