[msp] existing accounts (#362)

* [msp] existing accounts

* fix typo

src/pages/how-to/msp-portal.mdx

@@ -51,6 +51,10 @@ be able to switch to and manage the tenant account.
     If a user belongs to multiple groups with different roles, the highest permission role will be applicable.
 </Note>
 
+<Note>
+   Please see [Existing Account](#existing-account) if a Netbird account already exists in our system for the supplied tenant domain.
+</Note>
+
 3. To ensure that you have rights to manage the tenant, you need to verify the ownership of the tenant domain by adding
 a TXT DNS record to the tenant's domain:
 <p>
@@ -63,9 +67,22 @@ a TXT DNS record to the tenant's domain:
     <img src="/docs-static/img/how-to-guides/msp-portal/add-new-tenant-plan.png" alt="add-new-tenant-plan" className="imagewrapper"/>
 </p>
 
+### Existing Account
+
+When an account already exists in our system for the supplied tenant domain, you'll need to explicitly "Request Access" that the existing account Owner will have Grant the next time they login to their account:
+
+1. Press the "Request Access" button if the account already exists:
+<p>
+    <img src="/docs-static/img/how-to-guides/msp-portal/tenant-already-exists.png" alt="tenant-already-exists" className="imagewrapper-nig"/>
+</p>
+
+2. Ask the account Owner to log in to the dashboard and press "Grant Access"
+<p>
+    <img src="/docs-static/img/how-to-guides/msp-portal/tenant-grant-or-deny.png" alt="tenant-grant-or-deny" className="imagewrapper-nig"/>
+</p>
+
 <Note>
-    If you want to add an existing NetBird account as a tenant, please write us at msp@netbird.io providing the
-    tenant's owner email address.
+   When granted the existing account Owner role will change to Admin and their Subscription will be converted to a 3 days trial.
 </Note>
 
 ## Manage Tenant Networks