How to remove the data from array?

This is the data saving in my rethinkdb database. and i save the data for addtowatchlater is array. I use ember.js for frontend and tornado for backend and database for rethinkdb.

{ "accesstoken": "ajflasjjfasjfjasfasdfjasjflsajjfas" ,

"addtowatchlater": [

{"beatdescription": "aa" , "beatname": "aa" , "categoryname": "DJ" , "filename": "asfasdfasdfasdfa" , "id": "423423454352342344545423434" , "price": "aa" , "soldout": "No" , "stamp": "1510244267000" , "userid": "816fbfe8-ea81-4198-98f0-5fb0db01e25e" },

{ "beatdescription": "aa" , "beatname": "aa" , "categoryname": "DJ" , "filename": "asfasdfasdfasdfa" , "id": "423423454352342344545423434" , "price": "aa" , "soldout": "No" , "stamp": "1510244267000" , "userid": "816fbfe8-ea81-4198-98f0-5fb0db01e25e"}] ,

"id": "et4545er5454354354354353" ,

"role": "user" ,

"status": "Active" , }

I want to Remove one json data from addtowatchlater array field. when i remove i want like this for example.

{ "accesstoken": "ajflasjjfasjfjasfasdfjasjflsajjfas" ,

"addtowatchlater": [

{ "beatdescription": "aa" , "beatname": "aa" , "categoryname": "DJ" , "filename": "asfasdfasdfasdfa" , "id": "423423454352342344545423434" , "price": "aa" , "soldout": "No" , "stamp": "1510244267000" , "userid": "816fbfe8-ea81-4198-98f0-5fb0db01e25e"}

] ,

"id": "et4545er5454354354354353" ,

"role": "user" ,

"status": "Active" , }

I want like this. I Don't know how to do. please help me. please help me how to do. Reall Thanks