None of the responses are correct! Since you have chosen to download your Bank's RAW data using the menu item:  ... Banking / Bank Feeds / Import Web Connect ... (Quickbooks 2019 Desktop in Canada), that data is locked into the Quickbooks temporary data feed file processing engine.

They CANNOT easily be removed once committed but not reconciled, because they exist in a CHAIN of downloads for the periodicity and the arithmetic of your books. These are formal Bank records, and in some sense are legal documents and are NOT Quickbooks reconciled transactions.

You would normally proceed with a process to match every row in your monthly Bank-fed data file using a regular book-keeping chain or cycle, and match the incoming raw rows using either the button marked ...Add One to Quickbooks...  or  ...Add Multiple...".   

That process is called bank-feed reconciliation to account.  Too bad, because if you make a large error in the labels and names, or the batch mappings, you are doomed to re-establish and re-start the first month and the ENTIRE chain of Bank-fed data from the very first day, just like Adam and Eve. 

So, you better hope you have every file in the chain of those Web Connect files (*.qbo) that you downloaded since the day you purchased Quickbooks.  If you are doing monthly Bank-fed data loads, and you want to  manually edit the XML names and memo fields (using a text editor) BEFORE you load data into Quickbooks, you need to be VERY careful!  Never change any data fields within the RAW XML file EXCEPT the Name and Memo tags (if there is one). Every row in that XML has a set of tags,  <STMTTRN> </STMTTRN> that demarcate each row in your Bank-fed RAW data. You will be in trouble if you change any dates.  You CANNOT remove any single month or batch of months downloaded from your Bank feeds. If you made a mistake, and have already loaded them using Web Connect, and you want to remove the data,  you need to start the entire process from the very start for that particular account with it's configured Web Connect Bank feed (fed to you by the bank).

Yes, you must DELETE the entire Account from the Chart, by first removing  ANY dependent entries or amounts, and then reassign everything from SCRATCH. That is a PAIN, but you will learn, you ink-stained wretch, and Welcome to Quickbooks! This is another defect in the Canadian Desktop version of Quickbooks.