How should I change it?

[juliana0403]

Hi, guys.

The underlined part include a grammatical error.

How should I change it to be grammatically correct?

Thank You..

When he is expected, the sheets are changed and chasing the dog off the

patient's bed.

[mochimochi]

the dog is chased off the patient's bed

[Casiopea]

What about?

Ex: Before his arrival, the sheets are to be changed and the dog (is to be) chased off the patient's bed.