Difficult to: ～にくい
This structure indicates that something is difficult to do.
Examples
この漢字は書きにくいです。
This kanji is difficult to write.
この仕事はやりにくい。
This job is difficult to do.
その映画は見にくいです。
That movie is difficult to watch.
Quick check
この漢字は書き___にくいです。