XML File node insertion via linq

Question

Hi,

 

I have a xml list via API call, now to particular account_id I want to append my data. Below is the format of my file. Can someone let me know how can I do that. 

 

Also I need Linq query to extract data of one accout_id. 

 

<time_entries_set><time_entry_sets><time_entry_set><employee><account_id>4331659453</account_id></employee><start_date>2019-07-02</start_date><end_date>2019-07-02</end_date><time_entries/></time_entry_set><time_entry_set><employee><account_id>4331659452</account_id></employee><start_date>2019-07-02</start_date><end_date>2019-07-02</end_date><time_entries/></time_entry_set><time_entry_set><employee><account_id>4331659455</account_id></employee><start_date>2019-07-02</start_date><end_date>2019-07-02</end_date><time_entries/></time_entry_set><time_entry_set><employee><account_id>4331659454</account_id></employee><start_date>2019-07-02</start_date><end_date>2019-07-02</end_date><time_entries/></time_entry_set><time_entry_set><employee><account_id>4331659449</account_id></employee><start_date>2019-07-02</start_date><end_date>2019-07-02</end_date><time_entries/></time_entry_set></time_entries_set>