Getting something done by somebody else is expressed by the structure have + object + past participle.

I must have my hair cut.
I must have my shoes mended.
We must have our roof repaired.
He had his watch repaired.
She has had her photos taken.

Get can be used instead of have in this structure.

I must get my hair cut.
I must get my shoes mended.
We must get our roof repaired.
He got his watch repaired.
She has got her photos taken.

The structure have/get + object + past participle can also be used to talk about things that happen to us.
We had/got our roof blown off in the storm.

Last week I had/got my car stolen.

Rewrite the following sentences using have or get followed by a participle.

1. This cobbler mends my shoes for me.
2. A famous architect designed our house for us.
3. My shoes need mending.
4. My brother washed my car for me today.

Answers
1. I get/have my shoes mended by this cobbler.
2. We got/had our house designed by a famous architect.
3. I must get/have my shoes mended.
4. I got/had my car washed by my brother today.